How to customize the configuration file of the official PostgreSQL Docker image?

Question

I\'m using the official Postgres Docker image trying to customize its configuration. For this purpose, I use the command sed to change max_connections

Answer 1

You can put your custom postgresql.conf in a temporary file inside the container, and overwrite the default configuration at runtime.

To do that :

• Copy your custom postgresql.conf inside your container
• Copy the updateConfig.sh file in /docker-entrypoint-initdb.d/

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Dockerfile

FROM postgres:9.6

COPY postgresql.conf      /tmp/postgresql.conf
COPY updateConfig.sh      /docker-entrypoint-initdb.d/_updateConfig.sh

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updateConfig.sh

#!/usr/bin/env bash

cat /tmp/postgresql.conf > /var/lib/postgresql/data/postgresql.conf

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At runtime, the container will execute the script inside /docker-entrypoint-initdb.d/ and overwrite the default configuration with yout custom one.